package com.bluebox;
/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */


import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.UnsupportedEncodingException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import javax.activation.DataHandler;
import javax.activation.DataSource;
import javax.mail.Message;
import javax.mail.MessagingException;
import javax.mail.Multipart;
import javax.mail.Part;
import javax.mail.internet.ContentType;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeBodyPart;
import javax.mail.internet.MimeMessage;
import javax.mail.internet.MimePart;
import javax.mail.internet.MimeUtility;
import javax.mail.internet.ParseException;
import javax.mail.util.ByteArrayDataSource;

/**
 * Parses a MimeMessage and stores the individual parts such a plain text,
 * HTML text and attachments.
 *
 * @since 1.3
 * @version $Id: MimeMessageParser.java 1606710 2014-06-30 12:29:13Z ggregory $
 */
public class MimeMessageParser
{
	/** The MimeMessage to convert */
	private final MimeMessage mimeMessage;

	/** Plain mail content from MimeMessage */
	private String plainContent;

	/** Html mail content from MimeMessage */
	private String htmlContent;

	/** List of attachments of MimeMessage */
	private final List<DataSource> attachmentList;

	/** Is this a Multipart email */
	private boolean isMultiPart;

	private List<String> cids = new ArrayList<String>();
	private Map<String,DataSource> cidDsMap = new HashMap<String,DataSource>();

	/**
	 * Constructs an instance with the MimeMessage to be extracted.
	 *
	 * @param message the message to parse
	 */
	public MimeMessageParser(final MimeMessage message)
	{
		attachmentList = new ArrayList<DataSource>();
		this.mimeMessage = message;
		this.isMultiPart = false;
	}

	/**
	 * Does the actual extraction.
	 *
	 * @return this instance
	 * @throws Exception parsing the mime message failed
	 */
	public MimeMessageParser parse() throws Exception
	{
		this.parse(null, mimeMessage);
		return this;
	}

	/**
	 * @return the 'to' recipients of the message
	 * @throws Exception determining the recipients failed
	 */
	public List<javax.mail.Address> getTo() throws Exception
	{
		final javax.mail.Address[] recipients = this.mimeMessage.getRecipients(Message.RecipientType.TO);
		return recipients != null ? Arrays.asList(recipients) : new ArrayList<javax.mail.Address>();
	}

	/**
	 * @return the 'cc' recipients of the message
	 * @throws Exception determining the recipients failed
	 */
	public List<javax.mail.Address> getCc() throws Exception
	{
		final javax.mail.Address[] recipients = this.mimeMessage.getRecipients(Message.RecipientType.CC);
		return recipients != null ? Arrays.asList(recipients) : new ArrayList<javax.mail.Address>();
	}

	/**
	 * @return the 'bcc' recipients of the message
	 * @throws Exception determining the recipients failed
	 */
	public List<javax.mail.Address> getBcc() throws Exception
	{
		final javax.mail.Address[] recipients = this.mimeMessage.getRecipients(Message.RecipientType.BCC);
		return recipients != null ? Arrays.asList(recipients) : new ArrayList<javax.mail.Address>();
	}

	/**
	 * @return the 'from' field of the message
	 * @throws Exception parsing the mime message failed
	 */
	public String getFrom() throws Exception
	{
		final javax.mail.Address[] addresses = this.mimeMessage.getFrom();
		if (addresses == null || addresses.length == 0)
		{
			return null;
		}
		else
		{
			return ((InternetAddress) addresses[0]).getAddress();
		}
	}

	/**
	 * @return the 'replyTo' address of the email
	 * @throws Exception parsing the mime message failed
	 */
	public String getReplyTo() throws Exception
	{
		final javax.mail.Address[] addresses = this.mimeMessage.getReplyTo();
		if (addresses == null || addresses.length == 0)
		{
			return null;
		}
		else
		{
			return ((InternetAddress) addresses[0]).getAddress();
		}
	}

	/**
	 * @return the mail subject
	 * @throws Exception parsing the mime message failed
	 */
	public String getSubject() throws Exception
	{
		return this.mimeMessage.getSubject();
	}

	/**
	 * Extracts the content of a MimeMessage recursively.
	 *
	 * @param parent the parent multi-part
	 * @param part   the current MimePart
	 * @throws MessagingException parsing the MimeMessage failed
	 * @throws IOException        parsing the MimeMessage failed
	 */
	protected void parse(final Multipart parent, final MimePart part)
			throws MessagingException, IOException
			{
		if (part.getContentID()!=null)
			cids.add(part.getContentID());

		if (isMimeType(part, "text/plain") && plainContent == null
				&& !MimePart.ATTACHMENT.equalsIgnoreCase(part.getDisposition()))
		{
			plainContent = (String) part.getContent();
		}
		else
		{
			if (isMimeType(part, "text/html") && htmlContent == null
					&& !MimePart.ATTACHMENT.equalsIgnoreCase(part.getDisposition()))
			{
				htmlContent = (String) part.getContent();
			}
			else
			{
				if (isMimeType(part, "multipart/*"))
				{
					this.isMultiPart = true;
					final Multipart mp = (Multipart) part.getContent();
					final int count = mp.getCount();

					// iterate over all MimeBodyPart

					for (int i = 0; i < count; i++)
					{
						parse(mp, (MimeBodyPart) mp.getBodyPart(i));
					}
				}
				else
				{
					DataSource ds;
					this.attachmentList.add(ds = createDataSource(parent, part));
					if (part.getContentID()!=null) 
					{
						cidDsMap.put(part.getContentID(), ds);
					}
				}
			}
		}
			}

	/**
	 * Checks whether the MimePart contains an object of the given mime type.
	 *
	 * @param part     the current MimePart
	 * @param mimeType the mime type to check
	 * @return {@code true} if the MimePart matches the given mime type, {@code false} otherwise
	 * @throws MessagingException parsing the MimeMessage failed
	 * @throws IOException        parsing the MimeMessage failed
	 */
	private boolean isMimeType(final MimePart part, final String mimeType)
			throws MessagingException, IOException
			{
		// Do not use part.isMimeType(String) as it is broken for MimeBodyPart
		// and does not really check the actual content type.

		try
		{
			final ContentType ct = new ContentType(part.getDataHandler().getContentType());
			return ct.match(mimeType);
		}
		catch (final ParseException ex)
		{
			return part.getContentType().equalsIgnoreCase(mimeType);
		}
			}

	/**
	 * Parses the MimePart to create a DataSource.
	 *
	 * @param parent the parent multi-part
	 * @param part   the current part to be processed
	 * @return the DataSource
	 * @throws MessagingException creating the DataSource failed
	 * @throws IOException        creating the DataSource failed
	 */
	protected DataSource createDataSource(final Multipart parent, final MimePart part)
			throws MessagingException, IOException
			{
		final DataHandler dataHandler = part.getDataHandler();
		final DataSource dataSource = dataHandler.getDataSource();
		final String contentType = getBaseMimeType(dataSource.getContentType());
		final byte[] content = this.getContent(dataSource.getInputStream());
		final ByteArrayDataSource result = new ByteArrayDataSource(content, contentType);
		final String dataSourceName = getDataSourceName(part, dataSource);

		result.setName(dataSourceName);
		return result;
			}

	/** @return Returns the mimeMessage. */
	public MimeMessage getMimeMessage()
	{
		return mimeMessage;
	}

	/** @return Returns the isMultiPart. */
	public boolean isMultipart()
	{
		return isMultiPart;
	}

	/** @return Returns the plainContent if any */
	public String getPlainContent()
	{
		return plainContent;
	}

	/** @return Returns the attachmentList. */
	public List<DataSource> getAttachmentList()
	{
		return attachmentList;
	}

	/** @return Returns the htmlContent if any */
	public String getHtmlContent()
	{
		return htmlContent;
	}

	/** @return true if a plain content is available */
	public boolean hasPlainContent()
	{
		return this.plainContent != null;
	}

	/** @return true if HTML content is available */
	public boolean hasHtmlContent()
	{
		return this.htmlContent != null;
	}

	/** @return true if attachments are available */
	public boolean hasAttachments()
	{
		return this.attachmentList.size() > 0;
	}

	/**
	 * Find an attachment using its name.
	 *
	 * @param name the name of the attachment
	 * @return the corresponding datasource or null if nothing was found
	 */
	public DataSource findAttachmentByName(final String name)
	{
		DataSource dataSource;

		for (int i = 0; i < getAttachmentList().size(); i++)
		{
			dataSource = getAttachmentList().get(i);
			if (name.equalsIgnoreCase(dataSource.getName()))
			{
				return dataSource;
			}
		}

		return null;
	}

	/**
	 * Determines the name of the data source if it is not already set.
	 *
	 * @param part the mail part
	 * @param dataSource the data source
	 * @return the name of the data source or {@code null} if no name can be determined
	 * @throws MessagingException accessing the part failed
	 * @throws UnsupportedEncodingException decoding the text failed
	 */
	protected String getDataSourceName(final Part part, final DataSource dataSource)
			throws MessagingException, UnsupportedEncodingException
			{
		String result = dataSource.getName();

		if (result == null || result.length() == 0)
		{
			result = part.getFileName();
		}

		if (result != null && result.length() > 0)
		{
			result = MimeUtility.decodeText(result);
		}
		else
		{
			result = null;
		}

		return result;
			}

	/**
	 * Read the content of the input stream.
	 *
	 * @param is the input stream to process
	 * @return the content of the input stream
	 * @throws IOException reading the input stream failed
	 */
	private byte[] getContent(final InputStream is)
			throws IOException
			{
		int ch;
		byte[] result;

		final ByteArrayOutputStream os = new ByteArrayOutputStream();
		final BufferedInputStream isReader = new BufferedInputStream(is);
		final BufferedOutputStream osWriter = new BufferedOutputStream(os);

		while ((ch = isReader.read()) != -1)
		{
			osWriter.write(ch);
		}

		osWriter.flush();
		result = os.toByteArray();
		osWriter.close();

		return result;
			}

	/**
	 * Parses the mimeType.
	 *
	 * @param fullMimeType the mime type from the mail api
	 * @return the real mime type
	 */
	private String getBaseMimeType(final String fullMimeType)
	{
		final int pos = fullMimeType.indexOf(';');
		if (pos >= 0)
		{
			return fullMimeType.substring(0, pos);
		}
		else
		{
			return fullMimeType;
		}
	}

	/**
	 * Returns all cids'defined in the body parts of this message.
	 * @return
	 */
	public List<String> getCids() 
	{
		return cids;
	}

	public DataSource getDataSourceForCid(String cid)
	{
		if (cidDsMap.containsKey(cid)) {
			return cidDsMap.get(cid);
		}
		else {
			if (!cid.startsWith("<")) {
				cid = "<"+cid+">";
			}
			return cidDsMap.get(cid);
		}
	}

}
